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1.
Future Mother-In-Law.

The non-dirty (and probably more oft-intended) version of FMIL.
"I hate getting emails from my FMIL."
by invisibelle December 10, 2008
 
2.
Fuck my imaginary life.
Lochlan: Dude, even the imaginary version of Jane hates me!

Matt: Wow.. FMIL.
by Kookoo Hatterland August 08, 2010
 
3.
Fucking Mother-In-Law.

For when your vitrolic loathing needs to spill forth, but in a tastefully discreet acronym.
"Dude, she's such a bitch, I think she's ready to become the FMIL."
by sheertone March 23, 2006